Pharmacology

Mitral Valve Disease

The location of Mitral valve (bicuspid valve) in between left atrium and left ventricle of the heart. The valve is made of two tapered cups.

Mitral stenosis

  • The mitral valve orifice is narrowing by progressive fibrosis or thickening, heavy calcium deposition (Calcification) on the valve of leaflets and fusion of cups and subvalvular apparatus.
  • The mitral valve orifice is about 5 cm3 in normal diastole, but if it is diminished to less than 1 cm3 to produced severe mitral stenosis. In asymptomatic case it is about >2 cm2.

Clinical features of Mitral stenosis

Symptoms & Sign Causes
Breathlessness Pulmonary congestion, low cardiac output
Fatigue Low cardiac output
Palpitation Atrial fibrillation
Hemoptysis Pulmonary congestion, pulmonary embolism
Cough Pulmonary congestion
Chest pain Pulmonary hypertension
Thromboembolism Atrial stasis and atrial fibrillation
Murmur   Pressure gradient across the valve
loud first heart sound
opening snap
Crepitations     Left heart failure
Pulmonary oedema
Pleural effusions
atrial fibrilation Atrial dilation
mitral facies Low cardiac output
Right ventricular heave, loud P2 Pulmonary hypertension

Investigation of Mitral stenosis

  • ECG:
    • Right ventricular hypertrophy: tall R wave in V1-V3
    • P mitrale or atrial fibrillation
  • Chest X-ray
    • Enlarged left atrium and appendage
    • Signs of pulmonary venous congestion
  • Echo
    • Thickened immobile cusps
    • Reduced valve area
    • Enlarged left atrium
    • Reduced rate of diastolic filling of left ventricle
  • Doppler
    • Pressure gradient across mitral valve
    • Pulmonary artery pressure
    • Left ventricular function
  • Cardiac catheterization
    • Coronary artery disease
    • Pulmonary artery pressure
    • Mitral stenosis and regurgitation

Management

  • If pulmonary hypertension develops mitral valvotomy or mitral valve replacement should be considered.
  • Anticoagulant, cardiac glycoside (Digoxin), β-blockers or rate-limiting calcium antagonists, diuretics to control pulmonary congestion and antibiotic (Prophylaxis against endocarditis) should be consider.

Mitral balloon valvuloplasty and valve replacement

  • Mitral valvuloplasty is a procedure used to dilate the mitral valve. This treatment should be consider if there is no mitral regurgitation, non-calcified valve and subvalve, left atrium free from thrombus.
  • Valve replacement is indicated if there is substantial mitral reflux or if the valve is rigid and calcified
(Mitral valvuloplasty)
  • Mitral valvuloplasty: A guidewire is introduced into the right atrium (RA) from the femoral vein and the inferior vena cava (IVC). The inter-atrial septum is punctured, providing access to the left atrium and mitral valve. A balloon catheter is then advanced over the guidewire across the mitral valve and the balloon dilated to stretch the valve and reduce the degree of stenosis.

Mitral regurgitation

  • Acute mitral regurgitation causes rapid rise in left atrial pressure, but incase chronic mitral regurgitation gradually increase left atrial pressure as well as left ventricular diastolic pressure as a result of chronic volume overload of left ventricle.
(Mitral regurgitation: Murmur and systolic wave in left atrial pressure)

Causes of Mitral regurgitation

  • Mitral valve prolapse
  • Dilatation of the left ventricle and mitral valve ring (e.g. coronary artery disease, cardiomyopathy)
  • Damage to valve cusps and chordae (e.g. rheumatic heart disease, endocarditis)
  • Ischaemia or infarction of the papillary muscle
  • Myocardial infarction

Diagnosis

  • ECG
    • Left atrial hypertrophy
    • Atrial fibrillation
  • Chest X-ray
    • Enlarged left atrium
    • Enlarged left ventricle
    • Pulmonary venous congestion
    • Pulmonary Oedema (if acute)
  • Echo
    • Dilated left atrium, left ventricle
    • Dynamic left ventricle (unless myocardial dysfunction predominates)
    • Structural abnormalities of mitral valve
  • Doppler
    • Detects and quantifies regurgitation
  • Cardiac catheterization
    • Dilated left atrium, dilated left ventricle, mitral regurgitation
    • Pulmonary hypertension
    • Coexisting coronary artery disease

Treatment

  • Diuretics
  • Vasodilators if hypertension is present
  • Digoxin if atrial fibrillation is present
  • Anticoagulants if atrial fibrillation is present.

Hello! My name is Smrutiranjan Dash, a pharmacy professional. belonging from, Bargarh, Odisha. I have acquired Master degree in Pharmacy (Pharmacology) form B.P.U.T, Rourkela, Odisha. Currently I am working as an Assistant Professor at The pharmaceutical college, Barpali.

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